There is a limited choice of exercise equipment on the market today for exercising and strengthening the body's core muscles, including abdominals, obliques, and lower back muscles. Many of these equipment choices require that the user sit or lie down—putting pressure on the user's spine and coccyx. If the user must lie down in a prone position, typically the knees and/or thighs are engaged. In addition, many of these equipment choices are stationary, such as sit-up chairs and crunching machines, and are therefore not easily portable.
Many people who exercise regularly prefer to divide their exercise time between the various large groups of muscles in the body in order to focus their efforts for optimum results. For instance, during one training session, they will exercise the arms and upper body, during another training session, they will exercise the legs and lower body, and during even another training session they will exercise the abdominals and back muscles. Therefore, when exercising the abdominals, it is desirable to also be able to include the obliques, lower back, and other proximate muscles for a focused training session.
Furthermore, a portable piece of equipment is often sought. Many people do not want to have to search out a new gym whenever they travel, but at the same time do not want to forgo their regular exercise routine. Because most abdominal exercisers of the type found in gyms are fixed to the floor and/or use extensive frames to provide resistance, they are not conducive to travel. As a stop-gap solution, many people think to rely on exercise bands of the type that can be attached temporarily to doorknobs or doorframes or that can be stood on to be made stationary. A problem with these exercise bands is that they do not offer much stability and are difficult to control.